Silica gel coating, TPU-based projection curtain containing silica gel coating and preparation method of TPU-based projection curtain

Abstract

The invention discloses a silica gel coating, a TPU (Thermoplastic Polyurethane)-based projection curtain containing the silica gel coating and a preparation method of the TPU-based projection curtain. The silica gel coating is prepared from the following raw materials in parts by weight: 1 to 5 parts of polydimethylsiloxane, 1 to 5 parts of polyether type modified polydimethylsiloxane, 0.5 to 4 parts of octamethylcyclotetrasiloxane, 0.5 to 3.5 parts of triethoxysilane, 0.1 to 0.2 part of white gasoline, 0.1 to 0.2 part of decane, 0.5 to 1 part of a platinum vulcanizing agent, 0.8 to 2.5 parts of a reinforcing material, 0.01 to 0.03 part of a tackifier, 0.01 to 0.03 part of an antistatic agent, 0.5 to 2 parts of fluff powder, 0.05 to 0.1 part of extinction powder and 0.01 to 0.03 part of a dispersing agent. The silica gel coating provided by the invention is good in wear resistance and weather resistance, and the prepared TPU-based projection curtain material has excellent weather resistance and wear resistance, is environment-friendly and non-toxic, is anti-aging and anti-ultraviolet, is easy to clean and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of new material preparation, and specifically relates to a silicone coating, a TPU-based projection screen containing the silicone coating, and a preparation method. Background Art

[0002] Silicone coating is a functional coating material, which was first used to make waterproof coating and antifouling coating. With the development of material science, silicone coating is gradually used in a wider range of fields, such as electronics, automobiles, construction, etc. The main component of silicone coating is organic silicone resin, such as polydimethylsiloxane, etc. Fillers and functional additives are usually added according to the needs of use to meet different usage scenarios.

[0003] Projection screen is a special screen device for receiving projection images, which is mainly used in conference rooms, classrooms, home theaters and other scenes. In the prior art, there have been many reports on projection screens. For example, Chinese patent document CN107841240A provides a coating material for projection screen and a preparation method thereof, wherein the material composition by weight is: 80-100 parts of silicone resin, 20-30 parts of titanium dioxide, 5-10 parts of silicon dioxide powder, 2-5 parts of aluminum oxide, 0.2-0.5 parts of sodium oxide, 5-15 parts of magnesium silicate, 1-2 parts of magnesium oxide, 1.25-2.5 parts of curing agent, 0.25-1 parts of defoaming agent, and 0.75-1.25 parts of leveling agent; the ink for projection screen prepared by the above scheme has excellent thermal stability and good adhesion, but the wear resistance and weather resistance need to be further improved, and the particles such as titanium dioxide, silicon dioxide powder, aluminum oxide, etc. used are many, and their compatibility with silicone resin is poor, which is not conducive to dispersion. Another example is Chinese patent document CN118444519A, which provides a projection screen and a method for preparing the same, using preset light-absorbing particles and light-reflecting particles, where the light-absorbing particles are located on the side away from the substrate layer and gathered on one side of the surface of the grating prism structure layer; or, the light-absorbing particles are located on the side away from the substrate layer and gathered on the other side of the surface of the grating prism structure layer, so that the projection screen has both light-absorbing and light-reflecting functions, achieving the purpose of achieving light-absorbing and light-reflecting functions on the upper and lower sides of the grating prism structure layer. In the above technical solution, only the problems of poor visual effects and cost of the projection screen are fully considered, and other performance improvements of the projection screen such as weather resistance are not considered.

[0004] Therefore, based on the above-mentioned deficiencies in the prior art, the present invention is proposed. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a silicone coating, a TPU-based projection screen containing a silicone coating and a preparation method. The silicone coating has good wear resistance and weather resistance. The prepared TPU-based projection screen material has excellent weather resistance, wear resistance, environmental protection and non-toxicity, anti-aging, anti-ultraviolet, easy cleaning and other properties.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a silicone coating, which is prepared from the following raw materials in parts by weight: 1 to 5 parts of polydimethylsiloxane, 1 to 5 parts of polyether modified polydimethylsiloxane, 0.5 to 4 parts of octamethylcyclotetrasiloxane, 0.5 to 3.5 parts of triethoxysilane, 0.1 to 0.2 parts of white spirit, 0.1 to 0.2 parts of decane, 0.5 to 1 parts of platinum vulcanizer, 0.8 to 2.5 parts of reinforcing material, 0.01 to 0.03 parts of tackifier, 0.01 to 0.03 parts of antistatic agent, 0.5 to 2 parts of fluff powder, 0.05 to 0.1 parts of matting powder, and 0.01 to 0.03 parts of dispersant.

[0008] Preferably, the preparation of the reinforcing material comprises the following steps:

[0009] (1) Modification of rectorite: rectorite is mixed with sodium hydroxide and subjected to high temperature treatment. After the treatment, the mixture is crushed to obtain pre-modified rectorite;

[0010] (2) preparing chitosan acetic acid solution: adding chitosan to acetic acid solution, stirring and dispersing the chitosan evenly, and setting aside;

[0011] (3) Compounding with chitosan: adding the pre-modified rectorite obtained in step (1) to the chitosan acetic acid solution obtained in step (2), stirring, drying, grinding and sieving, to obtain modified rectorite;

[0012] (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, then react under stirring and heating conditions, then centrifuge, wash and dry to obtain modified silica;

[0013] (5) The modified rectorite obtained in step (3) and the modified silicon dioxide obtained in step (4) are sequentially added into water, stirred, centrifuged, washed and dried to obtain a reinforcing material.

[0014] Further preferably, in step (1), the mass ratio of rectorite to sodium hydroxide is 1:0.4-0.65, the high temperature treatment temperature is 780-805°C, and the treatment time is 0.5-4h.

[0015] More preferably, in step (2), the concentration of the acetic acid solution is 0.5-1.2 wt %, and the concentration of the chitosan is 1.2-2.5 wt %.

[0016] Further preferably, in step (3), the mass ratio of pre-modified rectorite to chitosan is 8 to 12:1; the stirring treatment temperature is room temperature, the treatment time is 24 to 72 hours; the drying temperature is 105 to 110° C., and the sieve mesh number is 100 to 150 meshes;

[0017] In step (4), the heating temperature is 30-40° C., the heating treatment time is 0.5-6 h; the mass ratio of silicon dioxide, N,N-dimethylformamide, succinic anhydride, and KH550 is 1:40-75:2.5-5.5:3.5-6.5;

[0018] In step (5), the mass ratio of modified rectorite, modified silicon dioxide and water is 1-2:0.5-1:10; the stirring treatment temperature is 30-40°C, and the treatment time is 0.5-4h.

[0019] In a second aspect, the present invention provides the use of the above-mentioned silicone coating in the preparation of a TPU-based projection screen.

[0020] In a third aspect, the present invention provides a method for preparing a TPU-based material for a projection screen, comprising the following steps:

[0021] S1. Evenly apply the organic silicone adhesive on one side of the TPU substrate, and then perform a curing treatment after the coating is completed, and cool it to obtain a primer layer;

[0022] S2. Weigh the raw materials of the silicone coating according to any one of claims 1 to 5 in proportion, mix and disperse them evenly, and then apply them on the release paper. Treat them at 75 to 85° C. to reach a semi-vulcanized state and then cover them on the base coating; then, perform pressure shaping and baking treatment to completely vulcanize them, and finally separate the release paper to obtain the silicone coating;

[0023] S3, applying a mixed solvent on the adhesive coating, and baking it;

[0024] S4, repeating steps S1 to S3 on the other side of the TPU substrate in sequence, and after the treatment is completed, a TPU-based material is obtained.

[0025] Preferably, in step S1, the preparation of the organic silicone adhesive comprises the following steps:

[0026] The hydrogen-containing polysiloxane, vinyl polysiloxane, dimethyldichlorosilane, octamethylcyclotetrasiloxane and platinum catalyst are mixed uniformly in weight proportions of 2-7 parts, 1-5 parts, 1-4 parts, 0.5-1.5 parts and 0.02-0.05 parts respectively, and then mixed with 4-8 parts of white spirit to obtain a product;

[0027] The coating amount of organic silicone adhesive is 20-30g / m 2 The curing temperature is 115-125°C and the curing time is 1-5 minutes.

[0028] Preferably, in step S2, the coating amount on the release paper is 200-300 g / m 2 , the treatment time at 75-85°C is 1-5min; the baking treatment temperature is 125-135°C, and the baking treatment time is 1-5min.

[0029] Preferably, in step S3, the mixed solvent is obtained by mixing the following raw materials by mass fraction: 45-55% dimethyl polysiloxane, 5-15% silicon dioxide, 25-35% decane, and 3-10% dimethyl silicone oil;

[0030] The coating amount is 20-30g / m 2 The baking temperature is 125-130°C and the baking time is 1-5 minutes.

[0031] Of course, the present invention also hopes to protect the TPU-based material for projection screen prepared by the method.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The TPU-based material provided by the present invention can be used to make a projection screen. The TPU-based material has excellent weather resistance, wear resistance, environmental protection and non-toxicity, anti-aging, anti-ultraviolet, easy cleaning and other properties, and has good comprehensive performance.

[0034] The preparation method of the TPU-based material provided by the present invention has the same double-sided treatment method, which includes primer treatment, silicone coating treatment and surface treatment; wherein the primer is to apply an adhesive on the TPU-based material, which is beneficial to the adhesion of the silicone coating; the silicone coating is used as the main material layer to give the material excellent comprehensive performance; the surface treatment provides the TPU-based material with good smoothness and dust resistance, wear resistance and adhesion effects.

[0035] In the present invention, the adhesive component used in the primer can withstand boiling in 100° C. water for one hour without delamination after being cured by baking at 120° C., and has a good bonding effect.

[0036] In the present invention, the silicone coating has very good weather resistance, wear resistance, non-toxic and tasteless, and the added additives such as matting powder and antistatic agent can give the silicone coating excellent antistatic and matting properties, which can meet the use of projection screens; the reinforcing material used further improves the weather resistance and wear resistance of the silicone coating. Specifically, the reinforcing material uses rectorite, chitosan and silicon dioxide as the main materials. Silicon dioxide itself is a very good filler particle, which can effectively improve the anti-corrosion, wear resistance, tensile and compressive properties of the silicone coating, but it is easy to agglomerate and will not form after a large amount. The coating system is easy to thicken, so the use of rectorite is introduced in the present invention, which reduces the use cost of the reinforcing material on the one hand, and complements the advantages of silica on the other hand, and synergizes to achieve the greatest effect; and rectorite as a filler has poor compatibility between resins and poor dispersibility, so chitosan rich in hydroxyl, carboxyl and other groups is introduced in the present invention for modification to improve its compatibility with resins; of course, another purpose of introducing chitosan is to consider the use of silica, so as to facilitate the synergistic improvement of the performance of the silica gel coating with the modified silica. The reinforcing material provided in the present invention, during use, is carboxylated to silica, which is beneficial to increase its surface polarity and improve its compatibility with the resin, and the introduced carboxyl groups and some hydroxyl groups contained in it can be combined with the rectorite compounded with chitosan through hydrogen bonds and weak forces, which helps to form a large network system, densely filled between the resins, improve the film density of the silica gel coating, and then improve the overall performance of the silica gel coating. In addition, the present invention also performs high temperature treatment on the rectorite, which is beneficial to improve its activity and improve the combination with chitosan. In short, the rectorite and silicon dioxide provided by the present invention, based on the use of chitosan, an organic substance, maximize the improvement of the performance of the silica gel coating by the reinforcing material. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a picture of the product obtained in Example 4. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below. All embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0039] Unless otherwise specified, the chemical reagents and production equipment involved in the present invention are purchased from the market.

[0040] Among them, organic silicone adhesive:

[0041] Hydrogen-containing polysiloxane, brand SH202, purchased from Hubei Longsheng Sihai New Materials Co., Ltd., with a hydrogen content of about 1.2;

[0042] Vinyl polysiloxane, brand DY-V401-5000, vinyl content 0.004 mol / 100 g, purchased from Shandong Dayi Chemical Co., Ltd.;

[0043] The platinum catalyst was 3% chloroplatinic acid isopropanol solution purchased from Dongguan Tianan Silica Gel Co., Ltd.

[0044] Among them, in the silicone coating:

[0045] Polydimethylsiloxane, brand SH-D3, purchased from Hubei Longsheng Sihai New Materials Co., Ltd.;

[0046] Polyether modified polydimethylsiloxane, brand SH204, purchased from Hubei Longsheng Sihai New Materials Co., Ltd.;

[0047] Platinum curing agent, brand name TNA-25PS, purchased from Dongguan Tianan Silicone Co., Ltd.;

[0048] Tackifier, terpene-styrene resin, brand KH-792, purchased from Dongguan Dinghai Plastic Chemical Co., Ltd.;

[0049] Antistatic agent, made from chloride, silicone oil, polyvinyl alcohol and vinyl chloride, brand K-595, purchased from Hangzhou Lin'an Dechang Electrostatic Technology Co., Ltd.;

[0050] Fluff powder, made of acrylic acid and polyurethane, was purchased from Shenzhen Xingsheng Pearlescent Chemical Pigment Co., Ltd.;

[0051] Matting powder, made of silicon dioxide, silicate, and talc, was purchased from Shenzhen Xingsheng Pearlescent Chemical Pigment Co., Ltd.;

[0052] The dispersant was casein, purchased from Guangdong Zhongtai Lianhua New Materials Co., Ltd.

[0053] Among them, in the mixed solvent:

[0054] Dimethyl polysiloxane, brand WS-1115, purchased from Jiangxi Wuseshi New Materials Co., Ltd.;

[0055] Dimethyl silicone oil, with a viscosity of about 5000 mPa·s (25°C), was purchased from Hubei Longsheng Sihai New Materials Co., Ltd.

[0056] Silicon dioxide was purchased from Aladdin Technology Co., Ltd. with a particle size of about 50 nm.

[0057] Rectorite was purchased from Hubei Mingliu Rectorite Technology Co., Ltd.

[0058] The deacetylation degree of chitosan was about 85%, and it was purchased from Shandong Yatu Biotechnology Co., Ltd.

[0059] The TPU material is purchased from the market. The present invention does not specifically limit its source and specification size, which is subject to what can be achieved by those skilled in the art.

[0060] Example 1

[0061] A silicone coating is prepared from the following raw materials by weight: 5g of polydimethylsiloxane, 3g of polyether modified polydimethylsiloxane, 3g of octamethylcyclotetrasiloxane, 2g of triethoxysilane, 0.15g of white oil, 0.15g of decane, 0.75g of platinum vulcanizer, 2.2g of strengthening material, 0.02g of tackifier, 0.02g of antistatic agent, 0.1g of fluff powder, 0.08g of matting powder, and 0.02g of dispersant.

[0062] Wherein, the preparation of the reinforcing material comprises the following steps:

[0063] (1) Modification of rectorite: rectorite and sodium hydroxide were mixed in a mass ratio of 1:0.5 and then subjected to high temperature treatment (795°C, 1 h). After the treatment, the mixture was crushed to obtain pre-modified rectorite;

[0064] (2) preparing chitosan acetic acid solution: adding chitosan to 1 wt % acetic acid solution to make the concentration of chitosan 2 wt %, stirring and dispersing the solution evenly, and setting aside;

[0065] (3) Compounding with chitosan: the pre-modified rectorite obtained in step (1) was added to the chitosan acetic acid solution obtained in step (2) at a mass ratio of pre-modified rectorite to chitosan of 10:1, and the mixture was stirred (room temperature, 48 h), dried (105° C., 2 h), and ground and sieved through 150 mesh to obtain modified rectorite;

[0066] (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, and then react under stirring and heating conditions (35°C, 2.5h), then centrifuge, wash and dry to obtain modified silica; wherein the mass ratio of silica, N,N-dimethylformamide, succinic anhydride and KH550 is 1:50:4:4.5;

[0067] (5) The modified rectorite obtained in step (3) and the modified silica obtained in step (4) are added to water in a mass ratio of 1.2:0.6:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0068] Example 2

[0069] A silicone coating is prepared from the following raw materials by weight: 5g of polydimethylsiloxane, 3g of polyether modified polydimethylsiloxane, 3g of octamethylcyclotetrasiloxane, 2g of triethoxysilane, 0.15g of white oil, 0.15g of decane, 0.75g of platinum vulcanizer, 2.4g of strengthening material, 0.02g of tackifier, 0.02g of antistatic agent, 0.1g of fluff powder, 0.08g of matting powder, and 0.02g of dispersant.

[0070] Wherein, the preparation of the reinforcing material comprises the following steps:

[0071] (1) Modification of rectorite: rectorite and sodium hydroxide were mixed in a mass ratio of 1:0.45 and then subjected to high temperature treatment (795°C, 1 h). After the treatment, the mixture was crushed to obtain pre-modified rectorite;

[0072] (2) preparing chitosan acetic acid solution: adding chitosan to 0.9 wt % acetic acid solution to make the concentration of chitosan 1.8 wt %, stirring and dispersing the mixture evenly, and setting aside;

[0073] (3) Compounding with chitosan: According to the mass ratio of pre-modified rectorite to chitosan of 9.5:1, the pre-modified rectorite obtained in step (1) was added to the chitosan acetic acid solution obtained in step (2), stirred (room temperature, 48 h), dried (105° C., 2 h) and ground and sieved through 150 mesh to obtain modified rectorite;

[0074] (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, and then react under stirring and heating conditions (35°C, 2.5h), then centrifuge, wash and dry to obtain modified silica; wherein the mass ratio of silica, N,N-dimethylformamide, succinic anhydride and KH550 is 1:50:4.2:4.8;

[0075] (5) The modified rectorite obtained in step (3) and the modified silica obtained in step (4) are added to water in a mass ratio of 1.2:0.6:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0076] Example 3

[0077] A silicone coating is prepared from the following raw materials by weight: 5g of polydimethylsiloxane, 3g of polyether modified polydimethylsiloxane, 3g of octamethylcyclotetrasiloxane, 2g of triethoxysilane, 0.15g of white oil, 0.15g of decane, 0.75g of platinum vulcanizer, 2.4g of strengthening material, 0.02g of tackifier, 0.02g of antistatic agent, 0.1g of fluff powder, 0.08g of matting powder, and 0.02g of dispersant.

[0078] Wherein, the preparation of the reinforcing material comprises the following steps:

[0079] (1) Modification of rectorite: rectorite and sodium hydroxide were mixed in a mass ratio of 1:0.52 and then subjected to high temperature treatment (795°C, 1 h). After the treatment, the mixture was crushed to obtain pre-modified rectorite;

[0080] (2) preparing chitosan acetic acid solution: adding chitosan to 0.95 wt % acetic acid solution to make the concentration of chitosan 1.9 wt %, stirring and dispersing the solution evenly, and setting aside;

[0081] (3) Compounding with chitosan: According to the mass ratio of pre-modified rectorite to chitosan of 10.5:1, the pre-modified rectorite obtained in step (1) was added to the chitosan acetic acid solution obtained in step (2), stirred (room temperature, 48 h), dried (105° C., 2 h) and ground and sieved through 150 mesh to obtain modified rectorite;

[0082] (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, and then react under stirring and heating conditions (35°C, 3h), then centrifuge, wash and dry to obtain modified silica; wherein the mass ratio of silica, N,N-dimethylformamide, succinic anhydride and KH550 is 1:50:4.2:4.8;

[0083] (5) The modified rectorite obtained in step (3) and the modified silica obtained in step (4) are added to water in a mass ratio of 1.2:0.65:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0084] Example 4

[0085] A method for preparing a TPU-based material for a projection screen comprises the following steps:

[0086] S1. Use a 120-mesh plum-shaped wheel and a scraper to evenly apply silicone adhesive on one side of the TPU substrate (the coating amount is 25g / m 2 ), after coating, curing treatment (120°C, 3min) was performed, and natural cooling was performed for 24h to obtain the primer layer;

[0087] S2, weigh the raw materials of the silicone coating described in Example 1 according to the proportion, mix and disperse them evenly, and then apply them on the release paper with texture (the coating amount is 260g / m 2), treated at 80°C for 2 minutes to reach a semi-vulcanized state and then covered on the base coating; subsequently, pressure-set by an 80kg round pressure wheel and a 2.5KG cylinder pressure, and then baked (130°C, 3 minutes) to fully vulcanize, and finally the release paper is separated to obtain a silicone coating;

[0088] S3, apply mixed solvent on the glue coating (coating amount is 25g / m 2 ), after baking (130℃, 3min), it is ready;

[0089] S4, repeating steps S1 to S3 on the other side of the TPU substrate in sequence, and after the treatment is completed, a TPU-based material is obtained.

[0090] The preparation of the organic silicone adhesive comprises the following steps:

[0091] Evenly mix 6g of hydrogen-containing polysiloxane, 3g of vinyl polysiloxane, 2g of dimethyldichlorosilane, 1g of octamethylcyclotetrasiloxane and 0.05g of platinum catalyst, and then mix with 6g of white oil to obtain the product.

[0092] The mixed solvent is obtained by mixing the following raw materials in mass fractions: 50% dimethyl polysiloxane, 8% silicon dioxide, 37% decane, and 5% dimethyl silicone oil.

[0093] Example 5

[0094] A method for preparing a TPU-based material for a projection screen comprises the following steps:

[0095] S1. Use a 120-mesh plum-shaped wheel and a scraper to evenly apply silicone adhesive on one side of the TPU substrate (the coating amount is 25g / m 2 ), after coating, curing treatment (120°C, 3min) was performed, and natural cooling was performed for 24h to obtain the primer layer;

[0096] S2, weigh the raw materials of the silicone coating described in Example 2 according to the proportion, mix and disperse them evenly, and then apply them on the release paper with texture (the coating amount is 260g / m 2 ), treated at 80°C for 2 minutes to reach a semi-vulcanized state and then covered on the base coating; subsequently, pressure-set by an 80kg round pressure wheel and a 2.5KG cylinder pressure, and then baked (130°C, 3 minutes) to fully vulcanize, and finally the release paper is separated to obtain a silicone coating;

[0097] S3, apply mixed solvent on the glue coating (coating amount is 25g / m 2 ), after baking (130℃, 3min), it is ready;

[0098] S4. Repeat steps S1 to S3 on the other side of the TPU substrate in sequence. After the treatment is completed, the TPU-based material is obtained.

[0099] Among them, the preparation of the organosilicon adhesive includes the following steps:

[0100] Mix 6 g of hydrogen-containing polysiloxane, 3 g of vinyl polysiloxane, 2 g of dimethyldichlorosilane, 1 g of octamethylcyclotetrasiloxane, and 0.05 g of platinum catalyst evenly, and then mix with 6 g of white spirit to obtain it.

[0101] Among them, the mixed solvent is obtained by mixing raw materials with the following mass fractions: 50% dimethyl polysiloxane, 8% silica, 37% decane, and 5% dimethyl silicone oil.

[0102] Example 6

[0103] A preparation method of a TPU-based material for a projection screen includes the following steps:

[0104] S1. Use a 120-mesh plum blossom wheel to evenly coat the organosilicon adhesive on one side of the TPU substrate through a scraper (the coating amount is 25 g / m 2 ). After the coating is completed, carry out curing treatment (120 °C, 3 min), and cool naturally for 24 h to obtain the bottom coating;

[0105] S2. Weigh the raw materials of the silica gel coating described in Example 3 in proportion, mix and disperse them evenly, and then coat them on the textured release paper (the coating amount is 260 g / m 2 ). After treating at 80 °C for 2 min to reach the semi-vulcanized state, cover it on the bottom coating; then, carry out pressure shaping and baking treatment (130 °C, 3 min) with an 80 kg heavy round pressure wheel and a 2.5 KG cylinder pressure to vulcanize completely, and finally separate the release paper to obtain the silica gel coating;

[0106] S3. Coat the mixed solvent on the glue coating (the coating amount is 25 g / m 2 ), and after baking treatment (130 °C, 3 min), it is okay;

[0107] S4. Repeat steps S1 to S3 on the other side of the TPU substrate in sequence. After the treatment is completed, the TPU-based material is obtained.

[0108] Among them, the preparation of the organosilicon adhesive includes the following steps:

[0109] Mix 6 g of hydrogen-containing polysiloxane, 3 g of vinyl polysiloxane, 2 g of dimethyldichlorosilane, 1 g of octamethylcyclotetrasiloxane, and 0.05 g of platinum catalyst evenly, and then mix with 6 g of white spirit to obtain it.

[0110] The mixed solvent is obtained by mixing the following raw materials in mass fractions: 50% dimethyl polysiloxane, 8% silicon dioxide, 37% decane, and 5% dimethyl silicone oil.

[0111] Comparative Example 1

[0112] Compared with Example 1, the pretreatment of rectorite is omitted in Comparative Example 1. Specifically, in Comparative Example 1, a silicone coating is prepared from the following raw materials by weight: 5g polydimethylsiloxane, 3g polyether modified polydimethylsiloxane, 3g octamethylcyclotetrasiloxane, 2g triethoxysilane, 0.15g white oil, 0.15g decanter, 0.75g platinum vulcanizer, 2.2g strengthening material, 0.02g tackifier, 0.02g antistatic agent, 0.1g fluff powder, 0.08g matting powder, and 0.02g dispersant.

[0113] Wherein, the preparation of the reinforcing material comprises the following steps:

[0114] (1) taking a rectorite raw material, crushing it and setting it aside;

[0115] (2) preparing chitosan acetic acid solution: adding chitosan to 1 wt % acetic acid solution to make the concentration of chitosan 2 wt %, stirring and dispersing the solution evenly, and setting aside;

[0116] (3) Compounding with chitosan: According to the mass ratio of rectorite to chitosan of 10:1, the rectorite obtained in step (1) was added to the chitosan acetic acid solution obtained in step (2), stirred (room temperature, 48 h), dried (105° C., 2 h) and ground and sieved through 150 mesh to obtain modified rectorite;

[0117] (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, and then react under stirring and heating conditions (35°C, 2.5h), then centrifuge, wash and dry to obtain modified silica; wherein the mass ratio of silica, N,N-dimethylformamide, succinic anhydride and KH550 is 1:50:4:4.5;

[0118] (5) The modified rectorite obtained in step (3) and the modified silica obtained in step (4) are added to water in a mass ratio of 1.2:0.6:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0119] Comparative Example 2

[0120] Compared with Example 1, the modification treatment of chitosan is omitted in Comparative Example 2. Specifically, in Comparative Example 2, a silicone coating is prepared from the following raw materials by weight: 5g polydimethylsiloxane, 3g polyether modified polydimethylsiloxane, 3g octamethylcyclotetrasiloxane, 2g triethoxysilane, 0.15g white oil, 0.15g decanter, 0.75g platinum vulcanizer, 2.2g strengthening material, 0.02g tackifier, 0.02g antistatic agent, 0.1g fluff powder, 0.08g matting powder, and 0.02g dispersant.

[0121] Wherein, the preparation of the reinforcing material comprises the following steps:

[0122] (1) Modification of rectorite: rectorite and sodium hydroxide were mixed in a mass ratio of 1:0.5 and then subjected to high temperature treatment (795°C, 1 h). After the treatment, the mixture was crushed to obtain pre-modified rectorite;

[0123] (2) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, and then react under stirring and heating conditions (35°C, 2.5h), then centrifuge, wash and dry to obtain modified silica; wherein the mass ratio of silica, N,N-dimethylformamide, succinic anhydride and KH550 is 1:50:4:4.5;

[0124] (3) The pre-modified rectorite obtained in step (1) and the modified silica obtained in step (2) are added to water in a mass ratio of 1.2:0.6:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0125] Comparative Example 3

[0126] Compared with Example 1, the modification treatment of silica is omitted in Comparative Example 3. Specifically, in Comparative Example 3, a silicone coating is prepared from the following raw materials by weight: 5g polydimethylsiloxane, 3g polyether modified polydimethylsiloxane, 3g octamethylcyclotetrasiloxane, 2g triethoxysilane, 0.15g white oil, 0.15g decanter, 0.75g platinum vulcanizer, 2.2g strengthening material, 0.02g tackifier, 0.02g antistatic agent, 0.1g fluff powder, 0.08g matting powder, and 0.02g dispersant.

[0127] Wherein, the preparation of the reinforcing material comprises the following steps:

[0128] (1) Modification of rectorite: rectorite and sodium hydroxide were mixed in a mass ratio of 1:0.5 and then subjected to high temperature treatment (795°C, 1 h). After the treatment, the mixture was crushed to obtain pre-modified rectorite;

[0129] (2) preparing chitosan acetic acid solution: adding chitosan to 1 wt % acetic acid solution to make the concentration of chitosan 2 wt %, stirring and dispersing the solution evenly, and setting aside;

[0130] (3) Compounding with chitosan: the pre-modified rectorite obtained in step (1) was added to the chitosan acetic acid solution obtained in step (2) at a mass ratio of pre-modified rectorite to chitosan of 10:1, and the mixture was stirred (room temperature, 48 h), dried (105° C., 2 h), and ground and sieved through 150 mesh to obtain modified rectorite;

[0131] (4) taking silicon dioxide and setting aside;

[0132] (5) The modified rectorite obtained in step (3) and the silicon dioxide obtained in step (4) are added to water in a mass ratio of 1.2:0.6:8, stirred (35°C, 2.5h), centrifuged, washed and dried to obtain a reinforcing material.

[0133] The performance test of the silicone coatings prepared in Example 1 and Comparative Examples 1 to 3 was carried out as follows:

[0134] The wear resistance is carried out in accordance with GB / T1768-2006. After the coating is applied, it is first treated at 80°C for 2 minutes and then at 130°C for 3 minutes.

[0135] Weather resistance is carried out according to ISO20340-2009.

[0136] Corrosion resistance test: soak in 6% sodium hydroxide first, then accelerate corrosion test at 35℃.

[0137] The test results are shown in Table 1.

[0138] Table 1

[0139]

[0140]

[0141] It can be seen from Table 1 that the silicone coating prepared in the present invention has good wear resistance, corrosion resistance and weather resistance. The performance of the TPU-based material prepared in Example 4 was tested, and the test results are shown in Table 2.

[0142] Table 2 Example 4 Material Test Results

[0143]

[0144]

[0145] It can be seen from Table 2 that the TPU-based material prepared in the present invention has good comprehensive performance.

[0146] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A silicone coating, characterized in that: The invention is prepared from the following raw materials in parts by weight: 1 to 5 parts of polydimethylsiloxane, 1 to 5 parts of polyether modified polydimethylsiloxane, 0.5 to 4 parts of octamethylcyclotetrasiloxane, 0.5 to 3.5 parts of triethoxysilane, 0.1 to 0.2 parts of white spirit, 0.1 to 0.2 parts of decane, 0.5 to 1 parts of platinum vulcanizing agent, 0.8 to 2.5 parts of reinforcing material, 0.01 to 0.03 parts of tackifier, 0.01 to 0.03 parts of antistatic agent, 0.5 to 2 parts of fluff powder, 0.05 to 0.1 parts of matting powder and 0.01 to 0.03 parts of dispersant.

2. A silicone coating according to claim 1, characterized in that: The preparation of the reinforcing material comprises the following steps: (1) Modification of rectorite: rectorite is mixed with sodium hydroxide and subjected to high temperature treatment. After the treatment, the mixture is crushed to obtain pre-modified rectorite; (2) preparing chitosan acetic acid solution: adding chitosan to acetic acid solution, stirring and dispersing the chitosan evenly, and setting aside; (3) Compounding with chitosan: adding the pre-modified rectorite obtained in step (1) to the chitosan acetic acid solution obtained in step (2), stirring, drying, grinding and sieving, to obtain modified rectorite; (4) Modification of silica: Add silica to N,N-dimethylformamide, stir and disperse it evenly, then add succinic anhydride and KH550, then react under stirring and heating conditions, then centrifuge, wash and dry to obtain modified silica; (5) The modified rectorite obtained in step (3) and the modified silicon dioxide obtained in step (4) are sequentially added into water, stirred, centrifuged, washed and dried to obtain a reinforcing material.

3. A silicone coating according to claim 2, characterized in that: In step (1), the mass ratio of rectorite to sodium hydroxide is 1:0.4-0.65, the high temperature treatment temperature is 780-805°C, and the treatment time is 0.5-4h.

4. A silicone coating according to claim 2, characterized in that: In step (2), the concentration of the acetic acid solution is 0.5-1.2 wt %, and the concentration of the chitosan is 1.2-2.5 wt %.

5. A silicone coating according to claim 2, characterized in that: In step (3), the mass ratio of pre-modified rectorite to chitosan is 8-12:1; the stirring treatment temperature is room temperature, the treatment time is 24-72 hours; the drying temperature is 105-110° C., and the sieve mesh number is 100-150 mesh; In step (4), the heating temperature is 30-40° C., the heating treatment time is 0.5-6 h; the mass ratio of silicon dioxide, N,N-dimethylformamide, succinic anhydride, and KH550 is 1:40-75:2.5-5.5:3.5-6.5; In step (5), the mass ratio of modified rectorite, modified silicon dioxide and water is 1-2:0.5-1:10; the stirring treatment temperature is 30-40°C, and the treatment time is 0.5-4h.

6. Use of the silicone coating according to any one of claims 1 to 5 in the preparation of TPU-based projection screens.

7. A method for preparing a TPU-based material for a projection screen, characterized in that: The steps include: S1. Evenly apply the organic silicone adhesive on one side of the TPU substrate, and then perform a curing treatment after the coating is completed, and cool it to obtain a primer layer; S2. Weigh the raw materials of the silicone coating according to any one of claims 1 to 5 in proportion, mix and disperse them evenly, and then apply them on the release paper. Treat them at 75 to 85° C. to reach a semi-vulcanized state and then cover them on the base coating; then, perform pressure shaping and baking treatment to completely vulcanize them, and finally separate the release paper to obtain the silicone coating; S3, applying a mixed solvent on the adhesive coating, and baking it; S4, repeating steps S1 to S3 on the other side of the TPU substrate in sequence, and after the treatment is completed, a TPU-based material is obtained.

8. The preparation method according to claim 7, characterized in that: In step S1, the preparation of the organic silicone adhesive comprises the following steps: The hydrogen-containing polysiloxane, vinyl polysiloxane, dimethyldichlorosilane, octamethylcyclotetrasiloxane and platinum catalyst are mixed uniformly in weight proportions of 2-7 parts, 1-5 parts, 1-4 parts, 0.5-1.5 parts and 0.02-0.05 parts respectively, and then mixed with 4-8 parts of white spirit to obtain a product; The coating amount of organic silicone adhesive is 20-30g / m 2 The curing temperature is 115-125°C and the curing time is 1-5 minutes.

9. The preparation method according to claim 7, characterized in that: In step S2, the coating amount on the release paper is 200-300 g / m 2 , the treatment time at 75-85°C is 1-5min; the baking treatment temperature is 125-135°C, and the baking treatment time is 1-5min.

10. The preparation method according to claim 7, characterized in that: In step S3, the mixed solvent is obtained by mixing the following raw materials by mass fraction: 45-55% dimethyl polysiloxane, 5-15% silicon dioxide, 25-35% decane, and 3-10% dimethyl silicone oil; The coating amount is 20-30g / m 2 The baking temperature is 125-130°C and the baking time is 1-5 minutes.

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